A CREATIVE COGNITION 215order of words in language grammars, or characteristic movements of an
object— will tend to be pulled into corresponding attractors and become
more predictable. Th e attractors take on myriad forms in the brain net-
works to form a constantly developing attractor landscape. It may be
better, in fact, to liken them to a seascape, because the medium in which
they exist is more turbulent than a landscape and because they are being
constantly updated with experience in a domain.
By the nature of experience, then, attractors in brain networks are
being constantly perturbed by streams of inputs. Sometimes these in-
puts will create temporary distortion, causing activity (patterns of nerve
impulses) to cycle around a central tendency. Th ese are limit cycle attrac-
tors, as with a swinging pendulum bumped off its regular swing into
a distorted loop. In contrast, activity oft en can be stretched to a critical
state by inputs with highly unusual values. Th e activity in the attractor
can fl ip out of its regular constraints to a more searching state, in which
new structures and responses can emerge.
Th is has been called a “chaotic” state. Generally speaking, it has been
found that attractors in the brain are maintained on the edge of such
criticality by constant perturbations from inside and outside the brain.^14
Sudden switching to chaotic states helps fi nd optimal resolutions to cur-
rent inputs very rapidly.
Just how such brain states create cognitive states is illustrated in
Walter Freeman’s studies. He has studied electrical activity in the brain
(electroencephalograms) during olfactory experiences in mice. Th ese sug-
gest that previous experiences with smells will have led to the emergence
of attractors, as just mentioned— one for each kind of smell. And these will
reside in the fi rst subcortical level in the brain, the olfactory bulb.
Novel experiences perturb a corresponding attractor, as just men-
tioned, but not with a fi xed response. Each new smell, Freeman reports,
produces “a global wave of activity” in those attractors. But failure to
reconcile the current with past experience creates chaotic activity in the
attractor landscape. Th is chaotic activity quickly resolves into an updated
attractor by adjusting par ameters, as recorded in cell connections. Th e
new resolution— the newly defi ned smell—is quickly passed on to the
cortex for further response.
This content downloaded from 139.184.14.159 on Tue, 17 Oct 2017 13:54:24 UTC